A printed circuit board (PCB) is an important component of an optical module, which may be used for electrically connecting chips.
A PCB may comprise a substrate as well as metal wires and solder pads which are formed on the substrate. A chip may be fixed on the PCB by welding pins thereof to the solder pads. The PCB with chips may be installed and fixed in a housing of the optical module by connecting devices. Since space in the housing is small, heat dissipation of the chips may be poor.